package com.itheima.health.service;

import com.itheima.health.pojo.Member;

import java.util.List;

public interface MemberService {

    Member findById(Integer id);

    /**
     * 添加会员
     * 不存在则创建并返回，存在则更新非空字段并返回
     * @param member
     * @return
     */
    Member createOrUpdate(Member member);

    List<Integer> findMemberCountByMonths(List<String> months);
}
